CN113373949B - Protective structure for expansive soil slope and construction method - Google Patents

Abstract

The invention relates to the technical field of slope control, and discloses a protective structure for an expansive soil slope, which comprises a slope part, wherein an excavation surface is arranged along the slope part, the excavation surface is step-shaped, a plurality of layers of woven bag filling bodies are stacked at each step, each layer of woven bag filling body comprises a plurality of composite woven bag individuals which are tiled and arranged adjacently, each composite woven bag individual comprises a woven bag, an EPS (expandable polystyrene) plate layer is arranged on the inner surface of each woven bag, a mixture of expansive soil and EPS particles is filled in the woven bag, and a waterproof layer is arranged on the outer surface of each woven bag. The invention also discloses a construction method of the protective structure for the expansive soil side slope. The invention has the advantages of simple structure, light weight, high strength, weight reduction, heat preservation and energy buffering and elimination, simple construction method, greatly shortened construction period, great economic benefit and suitability for most expansive soil slope protection projects.

Description

A kind of protective structure and construction method for expansive soil slope

technical field

The invention relates to the technical field of slope prevention and control, in particular to a protective structure and a construction method for expansive soil slopes.

Background technique

Expansive soil is a special kind of unsaturated clay, which is widely distributed in my country. Its characteristics of water absorption expansion and water loss shrinkage make it very sensitive to changes in natural environment such as rainfall and evaporation. As a special clay with regional distribution and great harm, it has expansion and shrinkage, fissure and over-consolidation, and the three characteristics affect and relate to each other. Moreover, the change of its strength with water content often causes various engineering problems, which has a huge impact on the stability and safety of the project. Engineering construction in expansive soil areas will face potential threats such as building cracking, foundation deformation, and slope instability. The global annual economic loss caused by expansive soil problems exceeds 15 billion US dollars.

In order to solve the problems of shallow landslides on expansive soil slopes, geotextile bags are favored in slope engineering applications due to their advantages of high tensile and compressive strength, firm structure, long service life and obvious anisotropy. As a flexible structure, the geotextile bag is easy to deform, uses local materials, saves resources, and is simple in construction. While achieving good control effects, it also has a certain landscape effect. The expansive soil excavated and backfilled in the slope is put into the geotextile bag to reduce the direct contact between the expansive soil and the atmosphere to reduce evaporation, thereby slowing down the expansion and contraction deformation of the expansive soil, so it has broad application prospects in the field of slope engineering protection.

After searching the relevant patents of the existing geotextile bags, it is found that:

The utility model patent with the publication number CN211896157U discloses a reinforced geotechnical bag. The rectangular geotechnical bag body formed by the bag cloth in the fixed steel cage is stacked on the river bank to resist the impact of water flow, prevent soil erosion, and increase the service life. However, due to its fixed shape, it is not conducive to compaction between the geotextile bags, resulting in the reduction of strength.

The utility model patent with the publication number of CN204527998U discloses a flood control woven bag, which replaces the traditional straw flood control woven bag with geosynthetic material, and achieves the advantages of good quality, durability and low consumption. However, the design without considering waterproof and thermal insulation is not conducive to the application to expansive soil slopes.

The invention patent with publication number CN108708393A discloses a vibration buffer layer of a retaining wall. Each level of buffer material includes geogrid and geobag, and the geobag is filled with filler, which solves the problem that the existing vibration-absorbing EPS material produces large creep deformation under long-term load and affects the vibration-absorbing effect. Although the patent considers filling the EPS material with good characteristics into the geotextile bag, it does not fully utilize the characteristics of the EPS material; at the same time, the simple addition of the EPS material may not meet the specification requirements for expansive soil slopes.

The invention patent with publication number CN108589747A discloses a slope protection structure and a construction method for EPS light-weight embankment widening combined with planting bags. The EPS lightweight blocks are connected to each other by connecting steel bars to widen the embankment and fill the geotextile bag, which can reduce the additional stress and settlement deformation of the weak stratum, reduce the cost of foundation treatment, and have strong environmental adaptability. Although the patent also proposes the application of EPS materials, from the perspective of research content and innovation, it is different from the geotextile bag structure of glued EPS boards.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention provides a protective structure and a construction method for expansive soil slopes. By adding EPS boards and EPS particles, the geotextile bag can better play the role of thermal insulation and waterproofing, and at the same time, it also reduces the The weight of the soil can reduce the sliding force of the slope, thereby enhancing the stability of the slope and achieving the effects of waterproofing, heat preservation, fire prevention, shock absorption and load reduction.

The present invention can be realized through the following technical solutions:

A protective structure for expansive soil side slopes, comprising a side slope portion, an excavation surface is arranged along the side slope portion, the excavation surface is in the shape of steps, and each step is filled with multi-layer woven bags for filling. Each layer of woven bag filling body includes a plurality of composite woven bag individuals that are laid out next to each other, the composite woven bag individual includes a woven bag, the inner surface of the woven bag is provided with an EPS board layer, and the interior is filled with expansive soil A mixture of EPS particles, the outer surface is provided with a waterproof layer.

Further, the EPS board layer is pasted to the inner surface of the woven bag by gluing, and a gap is left from the mouth of the bag.

Further, the individual composite woven bag is in the shape of a flat cuboid.

Further, the individual woven bags in the upper and lower adjacent two-layer woven bag filling bodies are arranged in a staggered manner to avoid forming through seams.

A kind of implementation method based on the above-mentioned protective structure for expansive soil slope, comprising the following steps:

(1) Excavate part of the expansive soil slope to form a step shape, mix the excavated soil with EPS particles, and put them into the composite woven bag to form an individual composite woven bag;

(2) Stack the filled composite woven bags in dislocation on each step of the excavation, fill the joints of adjacent composite woven bags with EPS particles, then fill the gaps with lime soil, and finally put the woven bags on each layer. Waterproof mortar is applied on the filling body to form a multi-layer woven bag filling body;

(3) Saturated clay is covered on the slope where the woven bag filling is piled up to form the second waterproof layer;

(4) Hang reinforcement mesh on saturated clay and spray concrete to form a layer of concrete lining board.

Further, the stepped gradient is set to 1:1.5.

Further, the foundation base on the lowermost step is laid with a gravel cushion, which is rolled with a vibratory roller.

The beneficial technical effects of the present invention are:

The general geotextile bag glued with EPS board is used to protect the expansive soil slope. As a flexible component, it can effectively release the expansion force (unloading) released by the expansive soil slope when it encounters water, and compared with rigid components, it has a lighter weight. , Local materials, convenient construction, reduced workload and difficulty, economical and other advantages.

The invention has the advantages of simple structure, light weight, high strength, weight reduction, heat preservation, buffering and energy dissipation, simple construction method, greatly shortened construction period, and extremely economical benefits, and is suitable for most expansive soil slope protection projects.

Description of drawings

Fig. 1 is the general schematic diagram of the side slope protection structure of the present invention;

Fig. 2 is the structural representation of the individual composite woven bag of the present invention;

Among them, 1- individual composite woven bag, 2- EPS board, 3- expansive soil, 4- EPS particle, 5- crushed stone cushion, 6- drainage ditch.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.

As shown in Figures 1 and 2, the present invention provides a protective structure for expansive soil slopes, comprising a slope portion along which an excavation surface is provided, the excavation surface is stepped, and each excavation surface is stepped. The steps are filled with multi-layer woven bag fillers, and each layer of woven bag fillers includes a plurality of composite woven bag individuals 1 that are arranged in a flat lay and close to each other. The composite woven bag individual 1 includes a woven bag, and the inner surface of the woven bag is provided with There is an EPS board layer 2, the interior is filled with a mixture of expansive soil 3 and EPS particles 4, and a waterproof layer is provided on the outer surface. In this way, with the help of EPS board and EPS particles, the shortcomings of traditional geotextile bags such as inability to maintain heat, poor waterproof effect, and poor flame retardant effect are solved. Enhance the stability of the slope.

Specifically, the entire composite woven bag individual 1 is in the shape of a flat cuboid, which is convenient for subsequent stacking and filling. The EPS board layer 2 can be pasted to the inner surface of the woven bag by gluing, and a gap, such as a 20cm gap, is left from the bag mouth, which is convenient for Tie the woven bag, and fold the bag to the bottom of the woven bag to prevent the soil from leaking out of the bag. The waterproof layer on the outer surface of the woven bag is set as waterproof mortar, which is cationic chloroprene latex, which is a polymer molecule modified waterproof and anti-corrosion system. destroy.

In addition, each woven bag individual 1 in the two-layer woven bag filling body adjacent up and down is staggered to avoid forming through seams.

The present invention also provides an implementation method based on the above-mentioned protective structure for expansive soil slope, comprising the following steps:

(1) Excavate part of the expansive soil slope to form a step shape. The height of the step can be set at about 0.8m and the slope is 1:1.5. Layer 5, the gravel cushion is made of well-graded and unweathered gravel or crushed stone, the maximum diameter is less than 50mm, and the thickness of the gravel cushion is 0.3m. After laying, it needs to be rolled with a vibratory roller.

Then, after mixing the excavated soil with EPS particles, it needs to be compacted after being put into the composite woven bag to discharge the excess pores in the bag to form a flat cuboid-shaped composite woven bag individual. The economical effect is effectively exerted, in which the EPS particles are used to absorb the swelling force of the swelling soil in the bag.

(2) Stack a plurality of filled composite woven bags in dislocation on each step of the excavation, fill the joints of adjacent composite woven bags with EPS particles, and then fill the gaps with lime soil such as 8% lime soil , try to be airtight, and finally apply waterproof mortar on each layer of woven bag filling to form a multi-layer woven bag filling;

In this way, EPS particles and lime soil are used for leveling between adjacent geotextile bags. The EPS particles are used to absorb excess expansion force, and the lime soil acts as a mortar-like bond, so that the geotextile bag can form a better whole, so as to achieve buffer reduction. The effect of earthquakes can also prevent water from entering the slope.

(3) Cover the slope with the woven bag backfill covered with saturated clay to form a second waterproof layer, which can cover saturated clay with a thickness of 1 m. Compared with unsaturated soil, saturated soil has stable properties and is suitable as a sealing layer;

(4) Hang reinforcement mesh on saturated clay and spray concrete to form a layer of concrete lining board to enhance structural integrity and stability.

For better drainage, a drainage ditch 6 can be set up at the foot of the protective slope, so that the water flowing down the slope can enter the drainage ditch for drainage.

Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes may be made to these embodiments without departing from the principle and essence of the present invention. Modifications, therefore, the scope of protection of the present invention is defined by the appended claims.

Claims (6)

1. The utility model provides a protective structure for native side slope expands, includes side slope portion, follows side slope portion is provided with the excavation face, the step form is personally submitted in the excavation, and every step department all piles up multilayer braided bag obturator, and every layer of braided bag obturator is individual including a plurality of compound braided bags of tiling adjacent range, its characterized in that: the composite woven bag is individual including the braided bag, the internal surface of braided bag is provided with the EPS sheet layer, and inside is filled up the mixture of inflation soil and EPS granule, and the surface is provided with the waterproof layer, the EPS sheet layer is pasted to the internal surface of braided bag through the veneer, and leaves the space apart from the sack.

2. A protective structure for an expansive soil slope according to claim 1, wherein: the composite woven bag is flat and cuboid.

3. A protective structure for an expansive soil slope according to claim 1, wherein: the woven bags in the upper and lower adjacent two layers of woven bag filling bodies are arranged in an individual staggered mode, and therefore the through seams are avoided.

4. A method for implementing a protection structure for an expansive soil slope according to claim 1, which comprises the following steps:

(1) excavating part of soil body of the expansive soil side slope to form a step shape, mixing the excavated soil body with EPS particles, and then filling the mixture into composite woven bags to form composite woven bag individuals;

(2) the filled composite woven bag bodies are piled on each step of the excavation in a staggered mode, EPS particles are filled at the connection positions of adjacent composite woven bag bodies, then the gaps are filled with lime soil, and finally waterproof mortar is coated on each layer of woven bag filling body to form a multi-layer woven bag filling body;

(3) covering saturated clay on the slope on which the woven bag filling body is piled up to form a second waterproof layer;

(4) and hanging a reinforcing mesh on the saturated clay, and spraying concrete to form a layer of concrete lining plate.

5. The method of implementing a protective structure for an expansive soil slope according to claim 4, wherein: the gradient of the step shape is set to be 1: 1.5.

6. The method of implementing a protective structure for an expansive soil slope according to claim 4, wherein: and paving a gravel cushion layer on the foundation base on the lowest step, and rolling by using a vibratory roller.

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